Randomly, IntelliSense will stop automatically displaying in C# files (when "." is pressed, or just typing). Ctrl-Space will still bring it up, but I find that to be too much work. If I close the file and re-open it, IntelliSense again works as expected.
If i had to make a guess, I think it usually happens after their are some errors in the file, like the parsing of the file fails and then never recovers, even after the errors are fixed.
(I'm using VS2010, Resharper 6.1)
Anyone else experience this?